Same stuff as everyone else said.
I find it nearly impossible ti ride my own pace the first lap, ending up with arm pump early and having a hard time recovering. If I can get through the first three miles without overdoing it, I'm usually O.K.
That's just me, though.
The laps are around 9 miles, as I recall, and you'll end up running three laps.
If this is your first HS, run the Beginner Class. That is what it is for.
The Sandblasters HS is usually pretty good, but the course is rooty where it is old trail, and rooty where it is new trail. Most of it runs in a pine forest with fairly sandy soil. Did I mention lots of roots sticking up all over?
They have the best Enduro every year, in my book. Canceled last year due to Katrina, and maybe this year also, we'll see.
We have some good riding over near Mobile, if you are interested. We've got a 20 mile loop of single track. When you can make it three times around non stop, you're close to ready for an Enduro
Anyway, with Luck, Safety, and Reasonable Speed you'll do just fine
Karl